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Solvent Effect on the Grafting of an Organophilic Silane Onto Smectite‐type Clay: Application as Electrode Modifiers for Pesticide Detection
Author(s) -
Yanke Jenna Geralde Mbokana,
Dedzo Gustave Kenne,
Ngameni Emmanuel
Publication year - 2017
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/elan.201700144
Subject(s) - grafting , detection limit , silane , toluene , materials science , ethylene glycol , chemical engineering , carbon paste electrode , fourier transform infrared spectroscopy , nuclear chemistry , intercalation (chemistry) , swelling , solvent , chemistry , electrochemistry , inorganic chemistry , electrode , organic chemistry , cyclic voltammetry , chromatography , composite material , engineering , polymer
Abstract The effect of a non‐swelling (toluene) and a swelling (ethylene glycol (EG)) solvent on the grafting of an organophilic silane (octyltriethoxisilane) onto a smectitic clay was investigated. XRD patterns of the resulting materials reveals that the grafting occurred exclusively on the edges of the clay particles without intercalation, as evidenced by the non‐variability of the d‐value before and after the grafting. FTIR and TGA characterizations show that higher amount of silane was grafted when toluene was used as solvent. With EG, the clay particles were well‐dispersed and the grafting well controlled. These functionalized materials were used as carbon paste electrode modifiers to evaluate their abilities for electrochemical detection of organophilic pollutants at trace level. Carbendazim (cbz), a widely used fungicide was used as model compound. The clay functionalized in EG was the most efficient modifier, due to the combined effect of the characteristics of the pristine clay and the grafted silane. The electroanalysis experimental parameters were carefully optimized (pH 6.8, 15 min of accumulation time and 10 % of the modifier in the carbon paste). By varying cbz concentration, a 0.03 μM detection limit was obtained. The sensor provide very reproducible response but strongly affected by some metal ions interferences. By varying cbz concentration in river water, used as environmental sample model, higher detection limit was obtained (0.2 μM), due to interfering species.